Contact materials at elevated temperatures High Temperature Electronics
Agenda Introduction Soft Solder Alloys Sintering HotPowCon (HPC) Summary Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 2
Introduction Requirements: High power density High reliability High heat Conductivity Ambient condition more than 150 C Lead Free technology Live time more than 15 years Costs Assembly of a power module Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 3
Soft Solder Alloys Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 4
SPEZIALLEGIERUNGEN FÜR WEICHLOTE Speziallegierungen für Weichlote: Innolot J. Trodler Heraeus Materials Technology CMD-AM 06.12.2012 Seite 5
SPEZIALLEGIERUNGEN FÜR WEICHLOTE Speziallegierungen für Weichlote: Innolot Source: Abschlusspräsentation BMBF-Projekt LIVE; Akzeptanzkriterien thermisch hochbelasteter, miniaturisierter Lötverbindungen; J. Albrecht Siemens AG, CT MM6; Berlin 17.9.2008 J. Trodler Heraeus Materials Technology CMD-AM 06.12.2012 Seite 6
Special Soft Solder Alloy: HT1 b) Cross section after powder production (source: Müller, NMB 160804) Mapping of the powder; figure b) Ag (=Ag3Sn) (source Müller, NMB, 160804) Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 7
Special Soft Solder Alloy: HT1 a) b) a) SAC + In (without modifier) and b) SAC+In+KM (source Müller, NMB, 160804) Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 8
Special Soft Solder Alloy: HT1 Cross Section with 3,75% Ag, Ag3Sn Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 9
Special Soft Solder Alloy: HT1 Melting Range (Liquidus and Solidus) Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 10
Special Soft Solder Alloy: HT1 Technology Qualification TCT 30 /10 /30 @-40/+175 N=500 SnAg3.5 HT1 Innolot Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 11
Special Soft Solder Alloy: HT1 Product Qualification TCT 30 /10 /30 @-40/+125 N=1500/2000/3000/4000 CS N=1500 HT1 CS N=1500 SnAg3.5 CS N=4000 HT1 Source: Dudek, Fraunhofer ENAS CS N=2000 SnAg3.5 CS N=3000 SnAg3.5 Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 12
Sintering Table with the most important properties Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 13
Sintering: Processing magic 016 Items Paste Application Paste Drying Die Placement Sintering Process Stencil printing Drying of printed sinter paste Placement of die Sintering Step Equipment convetional printing equipment Conventional Box oven Die placemer with heated substrate holder Sinter press Parameter Stainless steel or PU squeegees Print Speed 30-70 mm/s Drying time 5-15 min drying temperature 60-120 C Drying in air Die Placement temperature 80-130 C Die Placement force min 0.03 MPa Sinter Pressure 20-40 MPa Sinter Temperature 230 C-280 C Sinter time 1-2 Minutes in air Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 14
Sintering: Processing magic 016 with DIE size 100mm² Items Paste Application Die Placement Sintering Process Printing/Dispensing Placement of Die Sintering Step Equipment Standard equipment Standard Die placer Box Oven Standard Parameter Peak Sinter Temperature 230 C- 280 C Sinter time 240 Minutes Parameter Standard die Placement Parameter Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 15
Sintering Thermography Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 16
Diffusion Soldering HPC HotPowCon Laufzeit 05.2011 04.2014 FKZ 13N11510 Coordination: Robert Bosch GmbH Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 17
Diffusion Soldering HPC Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 18
Diffusion Soldering HPC Investigation of thermo/mechanical reliability by experiment and simulation, source: Fraunhofer ENAS Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 19
Diffusion Soldering HPC Combination of thermal solidification and isothermal solidification could be the basis for a new quality of interconnection Phase diagram of a two element system Creating of intermetallic with Cu in a SnCu system. (Source: Fraunhofer IZM) Structure design through high melting intermetallic by using soft solder alloys based on solder paste soft solder alloy will be used based on Sn with a high metal concentration and additives Isothermal solidification at low/standard solder temperatures operation temperature higher than liquidus temperature after soldering Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 20
Diffusion Soldering HPC IGBT on DCB with SnCu solder paste (type 6) produced with a 20µm stencil IGBT on DCB with SnCu solder paste (type 6) and Cu powder produced with a 20µm stencil Combination of thermal solidification and isothermal solidification could be the basis for a new quality of interconnection Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 21
Diffusion Soldering HPC Materials WP1 Workpackage and Milestones M1 describes a combination of materials as well as the realization of that combination based on a lab application M2 has fixed the processes including a qualification of test equipment. Test & Simulation Design Process WP2 WP3 Application WP4 Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 22
Diffusion Soldering HPC Results DMA Changing of length [ratio] 0,25 0,2 0,15 0,1 0,05 0-0,05 140 240 340 440 Temperatur [ C] Changing of length [ratio] 0,25 0,2 0,15 0,1 0,05 0 150 200 250 300 350 400 450-0,05 Temperatur [ C] DMA with Cu particles Q1and SnCu reference, after soldering. There is no difference between Ref. and Paste with Copper in this Q1 quality. DMA with Cu particles Q2and SnCu reference, after soldering the temperature to melt again is more than 400 C. Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 23
Summary FEM: By the local damage-parameter D (read area 0,96 < D < 1 = delaminated) it shows a delamination at the corner of the Die. Means the delamination starts at app. -35 C. Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 Seite 24
Summary Soft Solder Alloys up to 175 C depends on the assembly concept Sintering already use for industry applications, different project for optimization (minimization) process temperature and pressure Government founded project: HotPowCon (HPC) as alternative for higher operation temperature > 300 C in project progress Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 25
Summary ~ 1000 C Sintering (process temperature 220 C) ~ 400 C HPC (process temperature 227 C + 20K) ~ 300 C High Lead solder (process temperature + 20K) ~ 220 C Lead Free solder (process temperature + 20K) Jörg Trodler/ Heraeus Materials Technology GmbH&Co.KG, Hanau, Germany / 7.11.12 26